Disclosure context

About tengu

Tengu is a recently emerged ransomware group first observed in October 2025, operating with apparent financial motivations and demonstrating a geographically diverse targeting approach across 49 documented victims. The group has primarily focused their operations on Morocco, the United States, India, Italy, and Indonesia, suggesting either opportunistic targeting or specific interest in these regions' economic sectors. Their victim profile spans multiple industries including technology, manufacturing, public sector, and agriculture and food production, indicating a broad targeting strategy rather than sector-specific focus. Due to the group's recent emergence and limited public documentation from established threat intelligence sources, specific details regarding their origin, affiliation status, technical methodology, encryption techniques, and operational structure remain largely undocumented by major cybersecurity agencies and research organizations. No notable high-profile campaigns or law enforcement actions have been publicly reported by CISA, FBI, or prominent security researchers at this time. The group's current operational status appears active given their recent emergence, though comprehensive threat intelligence profiles from established sources have yet to be published due to their nascent presence in the ransomware landscape. The group has been linked to 57 public disclosures across our corpus. First observed on a leak site on October 23, 2025; most recent post May 21, 2026. The operation is currently active.

Timeline of this disclosure

February 18, 2026真言宗智山派成就院 listed by tenguon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Not Found sector, which has 4,859 disclosures indexed across all operators we track. Geographically, 真言宗智山派成就院 is reported in JP, a country with 88 ransomware disclosures in our corpus.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.

Ransomware victim disclosure

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真言宗智山派成就院

Claimed by tengu · listed 3 months ago

Age

since listed · data leaked

Status timeline

Listed
Feb 18, 2026
Data leaked

At a glance

Group: tengu
Status: Data leaked
Country: JP
Sector: Not Found
Listed on leak site: Feb 18, 2026

About the victim

AI dossier — public-source company profile

Jōju-in (成就院) is a traditional Japanese Buddhist temple belonging to the Shingon-shū Chisan-ha sect, one of the main branches of Shingon Buddhism in Japan. Located in Ueno, Tokyo (台東区東上野), the temple operates community activities including meditation sessions, study groups, and a small temple cafe, serving the local and broader Buddhist community.

Industry: Religious Organization & Buddhist Temple
Address: 東京都台東区東上野3-32-15

Attack summary

Severity: low — No proof files, screenshots, or data samples are documented in the leak post. No operational disruption is stated. A religious organization of this type typically holds limited sensitive data (donor records, member contacts) rather than regulated datasets; exfiltration of such data alone does not reach medium severity without demonstrated proof.

The Tengu group claims to have accessed the temple's systems and published data. The leak post provides no specific details about the scope of exfiltration or encryption activity.

low

What the group claims

Jōju-in is a traditional Japanese Buddhist temple belonging to the Shingon-shū Chisan-ha (真言宗智山派) sect, one of the main branches of Shingon Buddhism in Japan. The temple is located in Tochigi Prefecture (栃木県), specifically in the Northern Tochigi (栃木北部) region

The leak post

captured from the group's site

Crown Security is a technology company specializing in information security and digital systems, offering advanced solutions to protect corporate networks and data from breaches and cyberattacks The company focuses on providing security consulting and implementing integrated protection systems tailored to each organization's needs 
Sileno Companies Inc. A US company primarily operating in the hospitality and real estate sectors, its activities include: Hotel operation Property management Management of hotels' restaurants and bars Hospitality project development 22.9TB was encrypted in 14 hours on 3/5/2026 More than 67.07 GB was extracted 
Eos Technology srl is a company with 15 years of experience in the ICT sector, initially starting as an assembly and repair laboratory for PCs and peripherals. Over time, it has developed expertise that has allowed it to become a partner of various international brands. The company offers a range of services including IT assistance, multimedia services, help desk support, corporate security systems, and the design of virtual switchboards and video surveillance systems. Eos Technology srl aims to provide consulting services to clients navigating th…

Sources

Source

Indexed 3 months ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.